Based on data from the 2014 annual population change survey，this paper provides estimates of number and structure of the target couples of the selective and universal two-child policy，and conducts prediction of number of births and working age population under the two-child policy．The selective two-child policy has only limited effect on number of births，while the largest annual number of births under the universal two-child policy is roughly similar to the average annual number of births occurred in the 1980s to 1990s．Long-term decline in annual number of births is expected under the universal two-child policy．The universal two-child policy will somewhat postpone the time of China’s peak population which will be slightly larger．The universal two-child policy will have positive effect on optimizing China’s population structure and balancing its sex structure．